CPU Used Time for vCPU (%)

This chart is located in the Fault Tolerance view of the Virtual Machine Peformance tab. The chart is available only for collection levels 3 and 4.

Table 1. Data Counters

Chart Label

Description

used

Amount of used virtual CPU as a percentage of total available CPU on the primary and secondary virtual machines.

A high value indicates excessive use of CPU resources.

Counter: used

Stats Type: Delta

Unit: Percentage (%)

Rollup Type: Summation

Collection Level: 1

Chart Analysis

A large discrepancy in CPU usage between the primary and secondary virtual machines might indicate performance problems. The CPU ready, system, and wait times of each virtual machine should be synchronized. A large discrepancy in these values might indicate performance problems. Consider taking the following actions.

Table 2. CPU Performance Enhancement Advice

#

Resolution

1

Verify that the primary and secondary hosts are in the same CPU model family and have similar CPU configurations. For best results, use CPUs with the same stepping level.

2

Verify that the CPU resource reservations set for both virtual machines are consistent within the cluster. VMware HA plans for a worst-case scenario by considering all powered on virtual machines in a cluster and finding the maximum memory and CPU reservations.

3

Verify that the network and datastore connections for both virtual machines are similar.

4

Turn off power management (also known as power-capping) in the BIOS. If power management is enabled, the secondary host might enter lower performance, power-saving modes. Such modes can leave the secondary virtual machine with insufficient CPU resources, potentially making it impossible for the secondary to complete all tasks completed on a primary in a timely fashion.

5

Turn off hyperthreading in the BIOS. If hyperthreading is enabled and the secondary virtual machine is sharing a CPU with another demanding virtual machine, the secondary virtual machine might run too slowly to complete all tasks completed on the primary in a timely fashion.